Important American interests are at stake in what may seem, from a distance, arcane disputes within and among members of the European Union. Nonetheless, European debates over issues such as the common currency, immigration and economic regulations all reflect fundamental disputes over the EU’s ultimate purpose.

Whether and how EU members chose deeper political and economic integration fundamentally affects U.S. global security interests. For decades, beginning with the Marshall Plan, Washington encouraged closer cooperation among Europeans governments, perhaps leading to a “United States of Europe.” During the Cold War, this seemed to many Americans a sensible way to protect the Western alliance from fragmentation, and provide the unarguable benefits of reducing trade barriers.